All the alternatives you quote (assuming 'latest version') support Unicode, so they're not 'playing on the same pitch' as SyncBack freeware (which doesn't)
If the Simulated Run "reports the problem", does it give an error message? If so, what is it?
Have you set the Windows Locale?
Have you tried changing the copy mode to Windows Shell (or if you're using that now, change back)? See Modify > Copy/Delete tab > top option
Otherwise, I'm stumped, sorry